1. Field of Invention
The invention relates generally to thermal fluid ejectors with movable carriages.
2. Description of Related Art
Conventional thermal fluid ejectors with movable carriages have elements that are cooled through a physical connection to a heat sink and through natural heat convection from the heat sink to the ambient environment as the movable carriage moves over the guide rail. In some fluid ejector systems, this natural cooling becomes insufficient during times of high workload, such that the ejection elements tend to overheat. When the ejection elements start to overheat, some thermal fluid ejector systems are designed to automatically reduce the effective workload by decreasing the ejection rate, such that the natural cooling of the fluid ejectors again, becomes sufficient.
Improving the heat transfer away from the ejection elements would tend to solve this overheating problem. Such improvements would reduce the need for automatic reductions in the effective workload.
This invention provides systems and methods that improve the effective heat transfer rate from one or more thermal fluid ejectors of a fluid ejection system.
This invention separately provides systems and methods for increasing the effective heat transfer rate of heat generated by a thermal fluid ejector directly to the ambient atmosphere.
This invention separately provides systems and methods that increase effective flow rates of the ambient atmosphere over one or more thermal fluid ejectors of a fluid ejection system.
This invention separately provides one or more deflectors that direct a flow of ambient atmosphere across one or more printheads of a fluid ejector as a carriage on which the one or more thermal fluid ejectors are mounted moves during printing.
In various exemplary embodiments of the systems and methods according to this invention, a thermal fluid ejector cooling system improves the cooling of the thermal fluid ejector by taking advantage of the reciprocating motion of the movable carriage to increase the flow of the ambient atmosphere over the heat sink and/or one or more of the thermal fluid ejectors. The improved cooling obtained according to the systems and methods of this invention can be substantial and can decrease or even eliminate the need to automatically adjust the effective workload.
In various exemplary embodiments, the cooling systems according to this invention includes a passive structure, such as an air vane, that moves with the movable carriage and uses that movement to re-direct the ambient atmosphere to flow over the fluid ejector heads. The passive structure may be constructed of a variety of materials and may be an integral part of a thermal fluid ejection system or an add-on to an existing thermal fluid ejection system.
These and other features and advantages of this invention are described in, or are apparent from, the following detailed description of various exemplary embodiments of the systems and methods according to this invention.